I haven't used my XDK Workbench for a while and it seems, that I now need user credentials. Especially because I wanted to update it. I tried my credentials from this community, but it didn't work. Neither with my username or my email address.

The XDK Workbench does not need user credentials to work. This error message occurs due to some update functionality issues we are having right now. We are working on this problem and hope to solve it very soon!